Method of making armor-plate.



J. STRAUSS.

METHOD OF MAKING ARMOR PLATE. APPLICATION FILED MAE.31, 1905.

PATENTED MAR. 27, 1906.

UNITED STATES PATENT OFFICE.

JOSEPH STRAUSS, OF WASHINGTON, DISTRICT OF COLUMBIA.

METHOD OF MAKING ARMOR-PLATE.

Specification of Letters Patent.

Patented March 27, 1906.

Application filed March 31, 1905. Serial No. 253,187.

T all whom it may concern:

Be it known that I, JOSEPH STnAUss, of Washin ton, in the District of Columbia, have invented a certain new and useful Improvement in Methods of Making Armor-Plate; and I do hereby declare that the following is a full, clear, and exact descriptionthereof, reference being had to the accompanying drawings, in which Figure 1 is a face view of a piece of armorplate embodying my invention; Fig. 2, a cross-section of the same; and Fig. 3, a View in the nature of a diagram illustrating apparatus for welding.

The object of my invention is to provide a method of constructing armor-plate which, besides possessing other advantages, will result in a product possessing a hard outer or exposed surface, which will not flake off from the impact of a projectile striking the same, other than to a very limited extent, and having a tough inner portion; and to this end my invention consists in the method of making armor-plate substantially as hereinafter specified and claimed.

The desideratum in armor-plate is a hard exterior or exposed portion, sufiiciently hard and thick to prevent penetration of projectiles striking it, and having a tough inner portion capable of withstanding the racking strains to which the plate is subjected from the impact of projectiles. As well known, armor-plates have been constructed to fulfil these conditions both by a cementation process producing a decremental carburization of the plates from the outer face inward and by attaching or fastening to a large body of soft steel small plates of hard steel, the armor plate thus being a built-up or composite structure. By my invention I secure better results than are possible by either of the methods mentioned or by any other known to me, and in what I consider its best embodiment my plate in general respects is similar to those produced by the I second-mentioned methodthat is to say, as will be seen by reference to the drawings, it consists of a body or piece A, of the usual size, of a tough steel, and smaller plates or pieces B, of very hard steel, that constitute the face or exposed side of the armor-plate. I oin or unite the large tough body-piece A and the small hard plates B, by electric welding, as by welding them by means of electricity not only can a most perfect union be secured, so that what is essentially an integral structure can be pro duced, but there will be a diffusion decrementally of carbon from the hard small plates to the large plate of tough steel, this decremental diffusion of the carbon being obtained by proper manipulation of the temperture'of the plates. The hard small plates will thus be united to the tough back by a stratum. of metal that is decrementally carburized, and, as has before been said, the prodnot is essentially an integral one. Besides the diffusion of carbon from the hard small plates to the tough back the heatin of the portion of the latter next the smal plates will result in the mixing with the hot portions of the latter of alloys or elements that give the tough back its characteristics, so that its characteristics in some degree will be imparted to the small plates. The use of the small hard plates is important, because such size renders possible their perfect welding by electricity to the tough back. To secure the best results in the decremental carburizing of the stratum or section uniting the small hard plates and the tough back, it is desirable to exclude the air from the heated portions.

It is of course immaterial to the practice of my method what kind of apparatus for electric welding be employed; but in Fig. 3, in a conventional or diagrammatical way, I illustrate apparatus for welding the hard plates B to the body-piece A, which apparatus includes a source of electricity C, one pole of which is connected to the body-piece A and the other to a bar D, adapted to bear upon a hard plate B to be welded, to which bar D pressure is applied by a power-operated plunger E, so as to press the two pieces to be Welded together with the necessary force to effect their union. The post D and plunger E of course have a body of insulating material F interposed between them, and the body' piece A is supported by some suitable nonconductor.

To insure the Satisfactory welding of two pieces of metal by electric welding, it is essential that the surfaces of the two pieces to be joined shall be raised to the same or approximately the same temperature. To secure such equal temperature, it is necessary that the resistance of the two surfaces shall be the same. In order to secure like resistance, I employ means so that the area of the portion of the body-piece A to which a block B is to be joined shall be the same or approximately the same as the area of the abutting IJO and magnitu surface of said block, so that the same guank form and area tothe abutting surface of a block B, the roovesc. being of such depth le that the currentthrough the body-piece A will be ob ged to leave the body-piece from an area circumscribed by the area of the abutting face of a block B. Besides the control of the current,

so as to insure uniform or approximately uniform resistance at the surfaces to be welded,

.the grooves (1 also contribute to uniformity .of temperature-of the two surfaces by preventmg the lowering of the temperature of ortion of the surface of the body piece the Ato eheated by conduction.

Besides facilitating the welding operation and enabling the production of perfect results th use of the small plates is ofextreme import nce, because when the armor-plate is struck by a projectile the flaking oil" of the outer portion thereof if it occurswill be very ably slight spaces are limited in extent, because it will involve only the'surface plate or lates struck. Prefe rleft between the small lates to prevent any tendency of them to ake oif from the im actof a projectile, such tendency being obviated when the armorplate is bent or dished by the blow of a projectile, because ofthe relative movement toward each other of the hard plate or plates that are involved that 'is possible by reason of the existence of s aces between them. In

the absence of Sue spaces they .wouldimpinge upon and crowd each other uponthe dishing of the armorlate, with the result that they might be flaked or tornv off. .It is possible with my invention to have the outer hardened portion'of the armor-plate thicker than is the case of armobplate having a hardened outer surface produced by cemenlpassmgerasab- 'tation, because hard outer pieces can be em ployedfor the outer portion of my. plate hav- 'ing a thickness greater than the depth to plate can be hardened by cementa-' Which 21 tion.

It is to be understood, of course, that the scope of my invention is not limited to hard plates of any number or size or shape nor to anyparticular'relative thickness of the tough back and the hard outer portion ofmy ar- .mor-plate.

, 'Having thus described my invention, what. I claim is 1. The .method of making armor: plate,

which consists in electrically welding two metal late-form members grees o hardness.

2. The method of making arihorplate,

which consists in electrically welding toughsteel and hard-steel plate-form members.

3. The -method of making armor plate,

which consists in electrically welding to a tough body-plate a plurality of small plates. 4. ,The method of electrically welding small and largeplates, which consists in lothe area of the abutting surface of the small plate. A

.5. :T he method -of electrically :fwelding small and lar e plates which consists-in dividing the su ace of the large late, to which the small plates are to be we ded, bychanof different decalizing the current where the two plates abut, so that the area of the surface of the largeplate,subject ed to the action of the cur' rent, shall not be'substantiall'y greater than nels or grooves, placing the small plates on the-large plate so, that a small plate will be circumscrlbed by the grooves or channels and then passin a current through the abuttin surface of t e plates.

p n testimony that I claimthe foregoing I have hereunto set my hand.

JOSEPH STRAUSS.

Witnesses: GEO. S. BABcocK,

ROBERT CURRY= 

